The present invention relates to an on-the-move surface sampling probe used in conjunction with a mass spectrometer for the purpose of detecting chemical contaminated areas. Under present day conditions, considering the proliferation of chemical weapons, it is extremely important for combat forces to be able to mark and identify chemical areas of contamination, identify clear lanes of passage, and report this information to appropriate command elements.
In the past there has been no stand-alone chemical agent detector that could directly analyze ground surfaces for residual chemical agent contamination while being operated from a moving platform.
Prior art chemical agent detectors, one of which is known as the GErman Mass Spectrometer (GEMS) utilizes a gas chromatograh/quadrupole mass analyzer consisting of a heated sampling probe and mass analyzer assembly. The prior art probe comprised a heated sampling head and a 3.5 meter transfer column. In these prior art devices a liquid or solid sample is introduced into the sampling head by placing the sample in contact with a neared silicone coated wire membrane located at the end of the probe. The heated membrane vaporizes the chemical agent on contact which then passes through the membrane into the column and then to the mass spectrometer where the contaminating substance is analyzed. The problem with these prior art GEMS probes was that they could not be placed directly onto the ground from a moving platform, because contact with road and surface obstacles would damage the probe making it non-functional.
As a result of the aforementioned problems the prior art probes nave been modified to integrate the GEMS heated sampling probe with ground sampling devices. These ground sampling devices provide the means by which surface contamination can be brought from the ground to a GEMS probe while the vehicle is moving. These sampling devices act as transfer mechanism to pick up the contaminating agent, off the ground and deliver it to the GEMS probe. These prior art sampling devices generally consist of two independent booms which can be raised or lowered from within the vehicle either manually or automatically. Each boom contains some form of silicone rubber sampling element, such as a wheel. In the lowered position, the sampling element contacts the ground and rolls or drags freely. Periodically it is necessary to raise one of the booms while the other one is lowered. The element on the raised boom is then contacted to the GEMS' probe. If the sampling element is found to be clean, the boom and element are lowered and the second boom is raised and analyzed. This process is repeated until contamination is discovered. The contaminated sampling element has to be replaced with a clean element. A catcher or alignment device is required to insure that the sampled element is correctly positioned for the GEMS probe.
The problem with the aforementioned prior art device is that since both sampling booms share the same GEMS probe head, the alignment of the boom with the sampling head is critical. Testing of these prior art devices indicates that normal NBC Reconnaissance Systems movement alter the alignment to the point that the sampling system fails to operate. Another problem with the dual boom prior art device is the complexity required in the mechanical and electrical control circuits which must be used to properly time booms position. This complexity results in increased hardware costs, lack of reliability and more training time. A further problem with these prior art devices is the GEMS probe must be heated to maintain a rapid response to the sampled element. This design results in a mud build up on the probe and can result in the failure of the system to operate. Alignment devices used in the prior art design present an additional problem of cross contamination. A new sampling element may become contaminated by the catcher, thus giving misleading indications.